A catheter for implanting a cardiac pacing electrode within a right atrial septum, to stimulate the His bundle, includes a deflectable shaft having a wall that includes an adjustable segment, a pre-formed segment and a substantially straight distal segment. The pre-formed segment extends distally from a pull wire anchoring member of the adjustable segment and out of a single plane in which the adjustable segment is deflectable； and the substantially straight distal segment extends distally, directly from the pre-formed segment, along a plane oriented at an angle with respect to that in which the adjustable segment is deflectable, and over a length between approximately seven and nine millimeters. An arc through which the pre-formed segment extends is preferably greater than approximately 80 degrees and less than approximately 130 degrees, and the angle of the plane of the distal segment is preferably between approximately 40 and 60 degrees.
